Looking at alternative computer software solutions for a variety of reasons. This includes price, computer security, virus prevention and reliability.
Here are my notes and great that if it helps you, otherwise please understand what you are doing and not follow blindly.
All works expressed are my own and does not necessarily express the products or organisations mentioned here.

Wednesday, April 18, 2018

Create a Fragment App with Android Studio 3.1

This example, demonstrates how Fragments are created and loaded by an Activity class. Android Studio 3.1.1 is the IDE with Java 1.8.0 and an emulator is created with API 23. All this is running on Centos 7.

Step 1: Create an Empty project with vertical orientation

Open Android Studio and create a new project.
Application name: My Fragment
Click Next

This will provide a template to quickly create the rest of Fragments to be used with this Activity.

A total of 23 files are created in the app/src/main folder. By the time all steps are completed, there should be 29 files created in app/src/main folder.
=== Listing of 25 files at start of the project===
app/src/main/res/drawable/ic_launcher_background.xml
app/src/main/res/values/colors.xml
app/src/main/res/values/strings.xml
app/src/main/res/values/dimens.xml
app/src/main/res/values/styles.xml
app/src/main/res/mipmap-anydpi-v26/ic_launcher.xml
app/src/main/res/mipmap-anydpi-v26/ic_launcher_round.xml
app/src/main/res/drawable-v24/ic_launcher_foreground.xml
app/src/main/res/mipmap-hdpi/ic_launcher_round.png
app/src/main/res/mipmap-hdpi/ic_launcher.png
app/src/main/res/mipmap-mdpi/ic_launcher_round.png
app/src/main/res/mipmap-mdpi/ic_launcher.png
app/src/main/res/mipmap-xhdpi/ic_launcher_round.png
app/src/main/res/mipmap-xhdpi/ic_launcher.png
app/src/main/res/mipmap-xxhdpi/ic_launcher_round.png
app/src/main/res/mipmap-xxhdpi/ic_launcher.png
app/src/main/res/mipmap-xxxhdpi/ic_launcher_round.png
app/src/main/res/mipmap-xxxhdpi/ic_launcher.png
app/src/main/res/layout/content_main.xml
app/src/main/res/layout/activity_main.xml
app/src/main/res/menu/menu_main.xml
app/src/main/java/com/example/nicholas/myfragment/MainActivity.java
app/src/main/AndroidManifest.xml
===

Project Structure of application - Newly create project

A default project contains the following layouts activity_main.xml

CoordinatorLayout

AppBarLayout

Toolbar

an include layout tag

FloatingActionButton

content_main.xml

ConstraintLayout

TextView.

Edit the layout/activity_main.xml
In the CoordinatorLayout tag, insert following line before tools:context

tools:orientation="vertical"

Step 2: Add the buttons

Edit content_main.xml and remove the whole TextView tag. Replace with 2 buttons where you can just drag and drop the buttons from the widget list. Add a FrameLayout where we will position our Fragment layouts. Edit the button code as follows

Step 3: Create Analog Fragment

In AnalogFragment.java, replace import android.support.v4.app.Fragment with

import android.app.Fragment;

I plan to provide support only to Android API 23 and above.

Lets explore the Design editor.
Edit layout/fragment_analog.xml and click the tab Design. Notice that the default is FrameLayout.

On the left is the Palette, in the middle is the screen design + blueprint, on the right is the Attributes list. In the Design area, click the menu to choose API 23. Right click any where on the design and choose Convert FrameLayout to ConstraintLayout. Click "Ok".

Delete the default TextView in the design.

From the Palette, notice there is no AnalogClock which means it will have to be manually added. Click the Text tab and insert the following

There should be a wriggly red line at the text "this", click once then press Alt+Enter. Choose "Make MainActivityFragment implement android,view.View.OnClickListener". Choose "onClick(v:View):void" and press "OK".